BoilerFaultCodesTechnical description
Fan frost protection function active – fan speed outside the tolerance values
What causes this fault?
This fault occurs when the boiler's control system detects that the fan is not spinning at the required speed to safely clear exhaust gases. It is often triggered when the fan is physically stuck due to debris or ice, or when the electrical signals between the fan and the main control board are interrupted.
This fault is frequently seen during periods of extreme cold, as the frost protection mode can struggle if the air intake or flue becomes blocked by ice or snow.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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